Current marsh pollution has dramatic, negative effects on sea anemone's survival

Date:
January 7, 2022
Source:
Marine Biological Laboratory
Summary:
The starlet sea anemone Nematostella's growth, development, and
feeding ability are drastically impacted by present levels of common
pollutants found in one of its native habitats, the U.S. East Coast.



FULL STORY ========================================================================== Stationary marine organisms that don't ply the ocean, but spend their
lives rooted in one spot, have evolved impressive ways to capture
prey. The sea anemone Nematostella, for instance, burrows into salt marsh sediments and stays there for life. But it has specialized 'stinging
cells' that hurl toxins into passing prey, immobilizing the morsel so
the anemone can snatch it with its tentacles.


==========================================================================
New research from the Marine Biological Laboratory (MBL), however,
finds that Nematostella's growth, development, and feeding ability are drastically impacted by present levels of common pollutants found in
one of its native habitats, the U.S. East Coast.

"The numbers of Nematostella in the wild have been dramatically decreasing
over time," said senior author Karen Echeverri, associate scientist in the MBL's Bell Center for Regenerative Biology and Tissue Engineering. This
study pinpoints factors that threaten the species, which is already
under protection in the United Kingdom.

The MBL team focused on phthalates (plasticizers), chemicals that are
widely used in plastic packaging and other consumer products that wash
into the ocean; and potassium nitrate, which enters marshes through
runoff from lawn fertilizers.

When Nematostella embryos were exposed to phthalate and nitrate
concentrations commonly found in coastal environments (1-20 myM),
they showed a gross decrease in body size two weeks after exposure. The
animals also had fewer tentacles, and the tentacles that did grow were misshapen or uneven in length or number.

In addition, the pollutant-exposed animals had a severely reduced number
of stinging cells (cnidocytes), which they use as a defense mechanism
and to capture food.

"At a certain point, the animals just die, because they can't defend
themselves or feed themselves properly," said Echeverri.

Because Nematostella is sessile (stationary), it must constantly acclimate
to environmental changes, such as temperature and salinity. "They have
what we call adaptive plasticity; they are resilient to change," Echeverri said. "But we think there is a limit to that resilience. And as you bring
in more pollution, they reach that limit of resilience much faster."
The study is unusual in that it integrates assessment of the pollutants'
impact on Nematostella's microbiome. Led by MBL scientists Mitchell Sogin
and Emil Ruff, the team sequenced the microbiomes of animals after 10
days of pollutant exposure.

"Certain classes of microbes became much more dominant after exposure,"
said Echeverri. "How this affects the physiology of the animal, we don't completely know yet." Shifts in the microbiome can serve as sentinels
of change in the health of the host, as shown by prior studies in other animals, including corals and humans.

"A next step is to link changes in the Nematostella microbiome to changes
in the animal's development," Echeverri said.

Other studies of the effects of phthalates on embryonic development in vertebrates, including frogs and zebrafish, identified defects in body
growth similar to what was found in Nematostella. These include slower
body growth and defects of cells in the ectodermal lineage (such as the cnidocytes). Impacts on the endocrine system and on fertility have also
been documented in other species.

========================================================================== Story Source: Materials provided by Marine_Biological_Laboratory. Original written by Diana Kenney. Note: Content may be edited for style and length.


========================================================================== Related Multimedia:
* Nematostella_vectensis ========================================================================== Journal Reference:
1. Sylvia Klein, Victoria Frazier, Timothy Readdean, Emily Lucas,
Erica P.

Diaz-Jimenez, Mitchell Sogin, Emil S. Ruff, Karen Echeverri. Common
Environmental Pollutants Negatively Affect Development
and Regeneration in the Sea Anemone Nematostella vectensis
Holobiont. Frontiers in Ecology and Evolution, 2021; 9 DOI:
10.3389/fevo.2021.786037 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2022/01/220107164607.htm
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